Waterproof construction process for deep hole grouting filling treatment

Abstract

The invention discloses a waterproof construction process for deep hole grouting filling treatment, and relates to underground water control engineering in a foundation treatment process, which comprises the following steps of: (1) testing the elevation of a diving static water level in a superficial strong permeable layer, or testing the elevation of a water level of confined water rich in a hole or a fracture zone in a deep aquitard; (2) determining the top surface elevation of the aquitard at the to-be-grouted point; (3) determining the permeability coefficient of the cylinder to be applied and replaced; (4) calculating and determining the minimum radius of the replacement cylinder according to the pore-forming radius when the grouting pipe is installed in the grouting construction; (5) a replacement area with poor permeability is constructed at the to-be-gradually-arranged point position; (6) implanting the replacement cylinder into the replacement area; and (7) drilling the center of the replacement cylinder to the depth of the hole or the fracture zone, installing a grouting pipe in the replacement cylinder after drilling, and filling the grouting pipe with grouting. According to the method, the problems caused by a conventional grouting construction process can be solved, the construction cost can be reduced, and the grouting construction quality is guaranteed.

Description

Technical Field

[0001] The invention relates to a groundwater control project in a foundation treatment process, and in particular to a water-proof construction process for deep hole grouting and filling treatment. Background Art

[0002] In a large number of civil and industrial construction sites, there is a situation where the shallow stratum is a highly permeable layer, and the weakly permeable layer below the strong permeable layer has holes, broken zones and other unfavorable geological conditions that are not hydraulically connected to the upper strong permeable layer. When constructing buildings (structures) in such sites, if the foundation bearing capacity or foundation settlement verification does not meet the requirements of the specification due to the holes, broken zones and other unfavorable geological conditions in the lower weakly permeable layer, the grouting method can be used for filling treatment.

[0003] For the above situation, when the grouting construction technology is used to treat the grouting drilling and set the grouting pipe, the drilling will pass through the upper strong permeable layer and enter the weak permeable layer in the hole or broken zone. At this time, the conventional grouting construction technology will bring a series of treatment problems, which are mainly reflected in: First, the water level of the shallow strong permeable layer is high and in a saturated state. During the grouting drilling and grouting process, the upper groundwater will enter the hole and broken zone to be treated by the grouting through the drilling. When the deep holes and broken zones are widely distributed and the holes or broken zones have good connectivity, the shallow groundwater will cause a large amount of loss, causing the water level to drop and causing a sudden change in the hydrogeological conditions; second, when the deep holes or broken zones are connected to the high-altitude areas in the distance, the groundwater will flow out of the shallow groundwater, causing the water level to drop and the hydrogeological conditions to change suddenly. When the replenishment water source at the site is hydraulically connected and contains pressurized groundwater, the deep pressurized groundwater will enter the upper highly permeable layer through the borehole during the grouting and grouting process. When the replenishment water source is abundant, it may even overflow the surface and flood the construction site; thirdly, during the grouting process, if there is groundwater entering the lower holes and broken zones through the borehole from the upper highly permeable layer, or if pressurized water in the lower holes and broken zones enters the upper highly permeable stratum through the borehole, seepage pressure will be generated during the grouting process. Not only does it need to add anti-dynamic water dispersing admixtures for underwater grouting to the grouting material, which increases the cost of foundation treatment, but also the grouting is carried out under the influence of seepage pressure, and the construction quality is difficult to guarantee.

[0004] Therefore, when carrying out grouting construction on such sites, the market urgently needs a waterproof construction technology that can effectively isolate water, has low cost and reliable construction quality. Summary of the invention

[0005] The purpose of the present invention is to provide a waterproof construction process for deep hole grouting filling treatment, which can not only reduce the construction quality risk of grouting treatment under the influence of groundwater, but also reduce the material cost of grouting materials compared with conventional underwater grouting construction, and prevent the construction of grouting holes from causing groundwater in the aquifer to leak from the grouting holes and cause sudden changes in local hydrogeological conditions.

[0006] To achieve the purpose of the present invention, the technical solution adopted is: A waterproofing construction process for deep hole grouting filling treatment comprises the following steps: (1) Testing the static water level of shallow highly permeable layers, or testing the water level of confined water rich in holes or fractured zones in deep weakly permeable layers; (2) Determine the top elevation of the aquitard at the proposed grouting point; (3) Determine the permeability coefficient to be used for the replacement cylinder; (4) Calculate and determine the minimum radius of the replacement cylinder based on the hole radius during grouting construction and installation of the grouting pipe; (5) Create a replacement area with poor permeability at the proposed grouting point; (6) implanting the replacement cylinder into the replacement area; (7) Drill a hole in the center of the replacement cylinder to the depth of the hole or broken zone, and install a grouting pipe in the replacement cylinder after drilling, and fill the grouting pipe with grouting.

[0007] Furthermore, the test in step (1) is carried out by on-site drilling or exploration pits or trenches.

[0008] Furthermore, the elevation of the top surface of the aquitard at the proposed grouting point in step (2) is obtained by on-site drilling or by consulting existing data.

[0009] Furthermore, the permeability coefficient used for constructing the replacement cylinder in step (3) is obtained by experiment or by consulting existing data.

[0010] Furthermore, the calculation of the minimum radius of the displacement cylinder uses Darcy's law to derive the head loss caused by the seepage of groundwater in the displacement cylinder. It should be noted here that groundwater is the groundwater above the weak permeable layer (the first impermeable layer) in the stratum; confined water is the groundwater filled between two impermeable layers and with a water pressure higher than the top of the aquifer.

[0011] Furthermore, when the shallow aquitard is saturated with water and the holes or broken zones in the deep aquitard are free of water, the calculation formula for the minimum radius of the displacement cylinder is: ;

[0012] Among them, r 1 r is the radius of the hole in the displacement cylinder when constructing the grouting pipe; 2 is the radius of the displacement cylinder; h1 1 h1 is the elevation of the hole where the grouting pipe in the cylinder is placed and the hole wall is allowed to seep water; 2is the static water level elevation of the shallow diving outside the displacement cylinder; Q is the maximum allowable seepage water volume into the grouting hole in the cylindrical water-passing section inside the displacement body per unit time; k is the permeability coefficient of groundwater in the displacement body.

[0013] Furthermore, when there is no water in the shallow aquitard and the holes or broken zones in the deep aquitard contain confined water, the calculation formula for the minimum radius of the cylinder is: ;

[0014] Among them, r 1 r is the radius of the hole in the displacement cylinder when constructing the grouting pipe; 2 is the radius of the displacement cylinder; h2 1 h2 is the elevation of the confined water level in the holes or fractured zones in the deep aquitard; 2 is the elevation of the groundwater level allowed to seep out from the outside of the displacement cylinder; Q is the maximum allowable amount of water seeping into the grouting hole in the cylindrical water-passing section inside the displacement body per unit time; k is the permeability coefficient of groundwater in the displacement body.

[0015] Furthermore, the calculation formula for the maximum allowable outward seepage flow Q in the cylindrical water-passing section of the displacement body per unit time is: ;

[0016] Among them, k is the permeability coefficient of groundwater in the displacement body, r is the distance from any cylindrical water-passing section around the displacement cylinder to the center of the cylinder, and h is the water surface height.

[0017] Furthermore, the depth of the replacement zone in step (5) is 2 to 4 times the depth of the deep weakly permeable stratum. 2 , where r 2 is the radius of the displacement cylinder.

[0018] Furthermore, the drilling of the replacement cylinder and the installation of the grouting pipe in step (7) are both carried out inside the replacement cylinder or in the weakly permeable stratum.

[0019] The beneficial effects of the present invention are: The present invention adopts grouting filling to treat holes or broken zones in deep weakly permeable layers. When there is a large water pressure difference between the holes or broken zones in the shallow strong permeable layer and the deep weakly permeable layer, in order to reduce the influence of the dynamic water pressure generated during the grouting construction on the grouting quality, the method mainly adopts a material with poor permeability to replace part of the soil of the shallow strong permeable layer passed by the grouting hole at the proposed grouting point, so that the replacement cylinder of the material with poor permeability is embedded in the deep weakly permeable stratum, and the holes or broken zones in the deep weakly permeable stratum are treated by grouting filling by drilling holes inside the cylinder formed by the replacement.

[0020] 1. When the shallow stratum is saturated and there is no groundwater in the deep holes or broken zones, the construction process provided by the present invention can not only avoid the leakage of groundwater in the shallow stratum during drilling construction, but also the grouting filling treatment of the deep holes or broken zones will change the underwater operation into ordinary dry operation construction, and the influence of groundwater can be ignored when configuring the grouting materials, making the construction quality more reliable.

[0021] 2. When deep holes or broken zones are rich in groundwater and the pressure head is higher than the top surface of the weakly permeable layer, the construction process provided by the present invention can prevent the groundwater in the holes or broken zones from overflowing and entering the shallow strongly permeable layer without being easily detected. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings illustrate exemplary embodiments of the present invention and together with the description serve to explain the principles of the present invention. These drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification.

[0023] Figure 1 It is a cross-sectional schematic diagram of the stratum; Figure 2 is a schematic diagram of the arrangement of the displaced cylinders; Figure 3 This is a schematic diagram of deep hole grouting; Figure 4 Schematic diagram of replacing a cylinder to block the seepage of deep confined water to the shallow highly permeable layer; Figure 5 Schematic diagram of replacing the cylinder to prevent shallow water leakage through the grouting holes. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings and implementation methods. It is understood that the specific implementation methods described herein are only used to explain the relevant content, rather than to limit the present invention. It is also necessary to explain that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings.

[0025] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] Embodiment 1:

[0027] like Figure 1 , 2 As shown in Figures 3 and 5, the present invention provides a waterproof construction process for deep hole grouting filling treatment, when the shallow strong permeable layer is saturated with water and the holes or broken zones in the deep weak permeable layer are free of water, comprising the following steps:

[0028] (1) Testing the static water level of shallow highly permeable layers by on-site drilling or exploration pits or trenches;

[0029] (2) Obtain the top elevation of the aquitard at the proposed grouting point by on-site drilling or by consulting existing data;

[0030] (3) The permeability coefficient of the replacement cylinder to be used, obtained through experiments or reference to existing data;

[0031] (4) To prevent shallow water seepage from entering the grouting hole through the displacement cylinder or to control the amount of seepage water, the head loss caused by the seepage of water in the displacement cylinder is deduced using Darcy's law in combination with the hole radius when installing the grouting pipe during grouting construction, and the minimum displacement cylinder radius that can be used to control the amount of seepage water in the displacement cylinder is calculated;

[0032] The expression of Darcy's law is: (1) Where: k is the permeability coefficient of groundwater in the displacement body; i is the hydraulic gradient in the displacement body; A is the cross-sectional area of ​​seepage in the displacement body;

[0033] If the distance between any cylindrical water-passing section around the displacement cylinder and the center of the cylinder is r and the water surface height is h, then the water-passing section area A is: (2) The hydraulic gradient of the groundwater level on this section is: (3) Q is the seepage flow from the cylindrical water-passing section in the displacement body to the grouting hole per unit time: (4) (5) Integrate both sides (6) Where: r 1 r is the radius of the hole in the displacement cylinder when constructing the grouting pipe; 2 is the radius of the displacement cylinder; h1 1 h1 is the elevation of the hole where the grouting pipe in the cylinder is placed and the hole wall is allowed to seep water; 2 It is the static water level elevation of the shallow diving outside the displacement cylinder;

[0034] After integration, we get (7) tidy (8) (9) (5) According to the minimum radius of the displacement cylinder determined by the above method, the displacement area with poor permeability is constructed at the proposed grouting point, and the depth of the deep weak permeable stratum is 2 to 4 times r 2 ;

[0035] (6) Drill a hole in the center of the displacement cylinder to the depth of the hole or broken zone, with a drilling radius of r 1 , and install the grouting pipe. The drilling of the replacement cylinder and the installation of the grouting pipe are all inside the replacement cylinder or in the weakly permeable stratum. The groundwater in the shallow strong permeable layer cannot directly enter the holes or broken zones in the deep weakly permeable layer.

[0036] (7) Carry out normal filling and grouting according to the conventional grouting construction method.

[0037] In this embodiment 1, the order of steps (1) to (5) can be adjusted at will.

[0038] In this embodiment 1, the cylinder formed by displacement mainly prevents groundwater in the shallow highly permeable layer from seeping into the internal grouting holes and then flowing into the grouting treatment area in turn or flowing around through the embedded section into the grouting holes.

[0039] In this embodiment 1, after the grouting pipe is installed in the replacement cylinder, a sealing device can be used to seal the grouting pipe and the inner hole of the replacement cylinder, and the sealing device can be a sealing bag and / or a low-permeability sealing material.

[0040] Embodiment 2:

[0041] like Figure 1 , 2 As shown in , 3 and 4, the present invention provides a waterproof construction process for deep hole grouting filling treatment, when there is no water in the shallow strong permeable layer and the holes or broken zones in the deep weak permeable layer contain pressurized water, comprising the following steps:

[0042] (1) Obtain the elevation of the confined water level in the holes or fractured zones in the deep aquitard through on-site drilling or field testing methods such as exploration pits and trenches or by data review;

[0043] (2) Obtain the top elevation of the aquitard at the proposed grouting point by on-site drilling or by consulting existing data;

[0044] (3) The permeability coefficient of the replacement cylinder to be used, obtained through experiments or reference to existing data;

[0045] (4) To prevent deep confined water from seeping outward through the displacement cylinder into the shallow highly permeable layer or to control the amount of water seeping outward, the radius of the hole formed when installing the grouting pipe during grouting construction is combined with Darcy's law to deduce the head loss caused by the seepage of water in the displacement cylinder, and the minimum displacement cylinder radius that can be used to control the amount of water seepage in the displacement cylinder is calculated;

[0046] The expression of Darcy's law is: (1) Where: k is the permeability coefficient of groundwater in the displacement body; i is the hydraulic gradient in the displacement body; A is the cross-sectional area of ​​seepage in the displacement body;

[0047] If the distance between any cylindrical water-passing section around the displacement cylinder and the center of the cylinder is r and the water surface height is h, then the water-passing section area A is: (2) The hydraulic gradient of the groundwater level on this section is: (3) In unit time Q, the seepage volume from the cylindrical water-passing section in the displacement body to the grouting hole is: (4) (5) Integrate both sides (6) Where: r 1 r is the radius of the hole in the displacement cylinder when constructing the grouting pipe; 2 is the radius of the displacement cylinder; h2 1 h2 is the elevation of the confined water level in the holes or fractured zones in the deep aquitard; 2 To replace the groundwater level elevation allowed to seep out of the outer side of the cylinder;

[0048] After integration, we get (7) tidy (8) (9) (5) According to the minimum radius of the displacement cylinder determined by the above method, the displacement area with poor permeability is constructed at the proposed grouting point, and the depth of the deep weak permeable stratum is 2 to 4 times r 2 ;

[0049] (6) Drill a hole in the center of the displacement cylinder to the depth of the hole or broken zone, with a drilling radius of r 1, and install the grouting pipe. The drilling of the replacement cylinder and the installation of the grouting pipe are all inside the replacement cylinder or in the weakly permeable stratum. The groundwater in the shallow strong permeable layer cannot directly enter the holes or broken zones in the deep weakly permeable layer.

[0050] (7) Carry out normal filling and grouting according to the conventional grouting construction method.

[0051] In this embodiment 2, the order of steps (1) to (5) can be adjusted at will.

[0052] In this embodiment 2, the cylinder formed by displacement is mainly used to prevent pressurized water in holes or broken zones in deep weakly permeable layers. After the grouting holes are constructed in place and the pressurized water is depressurized, deep groundwater enters the grouting holes and seeps into the highly permeable layer through the displacement cylinder.

[0053] In this embodiment 2, after the grouting pipe is installed in the replacement cylinder, a sealing device can be used to seal the grouting pipe and the inner hole of the replacement cylinder, and the sealing device can be a sealing bag and / or a low-permeability sealing material.

[0054] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments / methods or examples. In addition, those skilled in the art may combine and combine the different embodiments / methods or examples described in this specification and the features of the different embodiments / methods or examples, unless they are contradictory.

[0055] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0056] It should be understood by those skilled in the art that the above embodiments are only for the purpose of clearly illustrating the present invention, and are not intended to limit the scope of the present invention. For those skilled in the art, other changes or modifications may be made based on the above disclosure, and these changes or modifications are still within the scope of the present invention.

Claims

1. A waterproof construction process for deep hole grouting filling treatment, characterized in that: The steps include: (1) Testing the static water level of shallow highly permeable layers, or testing the water level of confined water rich in holes or fractured zones in deep weakly permeable layers; (2) Determine the top elevation of the aquitard at the proposed grouting point; (3) Determine the permeability coefficient to be used for the replacement cylinder; (4) Calculate and determine the minimum radius of the replacement cylinder based on the hole radius during grouting construction and installation of the grouting pipe; (5) Create a replacement area with poor permeability at the proposed grouting point; (6) implanting the replacement cylinder into the replacement area; (7) Drill a hole in the center of the replacement cylinder to the depth of the hole or broken zone, and install a grouting pipe in the replacement cylinder after drilling, and fill the grouting pipe with grouting.

2. The waterproof construction process for deep hole grouting filling treatment according to claim 1 is characterized in that: The test in step (1) is carried out by on-site drilling or exploration pits and trenches; the top elevation of the aquitard at the proposed grouting point in step (2) is obtained by on-site drilling or by consulting existing data.

3. The waterproof construction process for deep hole grouting filling treatment according to claim 1 is characterized in that: The permeability coefficient used for constructing the replacement cylinder in step (3) is obtained by experiment or by consulting existing data.

4. The waterproof construction process for deep hole grouting filling treatment according to claim 1 is characterized in that: The minimum radius of the displacement cylinder is calculated using Darcy's law to derive the head loss caused by groundwater seepage in the displacement cylinder.

5. The waterproof construction process for deep hole grouting filling treatment according to claim 1 is characterized in that: When the shallow aquitard is saturated with water and the holes or broken zones in the deep aquitard are free of water, the calculation formula for the minimum radius of the displacement cylinder is: ； Among them, r1 is the radius of the drill hole in the displacement cylinder when the grouting pipe is installed; r2 is the radius of the displacement cylinder; h11 is the elevation of the height at which the hole wall is allowed to seep water in the grouting pipe installation hole in the displacement cylinder; h12 is the static water level elevation of the shallow diving outside the displacement cylinder; Q is the maximum allowable seepage water volume into the grouting hole in the cylindrical water-passing section of the displacement body per unit time; k is the permeability coefficient of groundwater in the displacement body.

6. The waterproof construction process for deep hole grouting filling treatment according to claim 1 is characterized in that: When there is no water in the shallow aquitard and the holes or broken zones in the deep aquitard contain confined water, the calculation formula for the minimum radius of the cylinder is: ； Among them, r1 is the radius of the drill hole in the displacement cylinder when constructing the grouting pipe; r2 is the radius of the displacement cylinder; h21 is the elevation of the pressurized water level in the holes in the deep weak permeable layer or the broken zone; h22 is the elevation of the groundwater level allowed to seep out of the outside of the displacement cylinder; Q is the maximum allowable seepage water volume into the grouting hole in the cylindrical water-passing section of the displacement body per unit time; k is the permeability coefficient of groundwater in the displacement body.

7. The waterproof construction process for deep hole grouting filling treatment according to claim 5 or 6, characterized in that: The calculation formula for the maximum allowable outward seepage water volume Q in the cylindrical water-passing section of the displacement body per unit time is: ； Among them, k is the permeability coefficient of groundwater in the displacement body, r is the distance from any cylindrical water-passing section around the displacement cylinder to the center of the cylinder, and h is the water surface height.

8. The waterproof construction process for deep hole grouting filling treatment according to claim 5 or 6, characterized in that: The depth of the replacement zone in step (5) is 2 to 4 times the depth of the deep weakly permeable stratum r2, where r2 is the radius of the replacement cylinder.

9. The waterproof construction process for deep hole grouting filling treatment according to claim 5 or 6, characterized in that: The drilling of the replacement cylinder and the installation of the grouting pipe in step (7) are both carried out inside the replacement cylinder or in the weakly permeable stratum.

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